A subject of the invention is a method to measure compaction properties of masses of the soil and other masses of similar kind. A mass specimen in a cylinder is pressed with standard pressure between an upper platen and a lower platen and the height of the specimen is measured in this method. A subject of the invention is also a device to accomplish earlier mentioned task. There is a frame, a specimen cylinder and a pressing device with an upper platen and a lower platen to be pressed against a specimen and placed in an angle with respect to the central axis of the specimen cylinder in this device.
To measure the change in density of masses of the soil and other masses of the kind like bituminous asphalt, the method of gyratory compaction is used and a device for gyratory compaction is needed. In already known methods of gyratory compaction the compaction is, in most cases, provided by pressing upper and lower platens of a cylindrical mould with standard pressure and rotating the other end of the cylinder abount a point, other than the central axis of the cylinder in a circular manner (so called gyratory-motion). Pressure and gyratory-motion create continuous sine-shaped reversal cross sectional deformation. Because of the pressure and the cross sectional deformation the soil particles of the specimen move with respect to each other and seek their way closer to each other so that compaction occurs and it densifies. Compaction and the growth in density are related to the properties of the material and the amount of cross sectional deformation. Thus, the change in density depends also on the number of gyrations. The number of gyrations (the angular velocity) as well as the temperature of the specimen are kept in the sphere at a test temperature according to the standards for the mixture in question during the compaction test. As the result the test provides the density corresponding to a known standard pressure and angle as the function of gyratory-motions. The shape and the location of the curve describing the densifying process depend on the material to be densified and its properties, the size of its particles and while mixtures are in question, the composition of separate components. Measured densifying properties can be utilized to determine the optimal composition and preparing methods for materials, like asphalt, used in earth and road works.
There are some various mechanisms known today that create gyratory compaction motion adjustable to a gyratory compaction device. Gyratory compaction motion in those devices is provided either by moving one end of the specimen cylinder in a circular manner (gyratory-motion) or by inclining the upper platen and the lower platen of the specimen cylinder on various sides by means of a rod adjusted in the middle of them with gyratory motions.
Measurements of the compaction properties by known methods and devices of gyratory compaction can be accomplished in a functional way, but their mechanisms that create the suitable gyratory compaction motion are complicated in construction and economically expensive and intricate to make because of the high requirements of precision.
The purpose of the invention is to create a method and a device to measure compaction properties of masses of the soil and other masses of the kind to prevent earlier mentioned problems.
The purpose of the invention is achieved by the method and the device, characteristic of which is what has been presented in the claims.
Characteristic to the method according to the invention is the fact that the mass specimen in the gyratory compaction device is rotated round the central axis that is incliner with respect to the upper and lower platen, thus generating densifying cross sectional deformations. When rotating a mass specimen about the central axis that has been rigidly supported the gyratory compaction devices may be relatively simple and exact. Manufacturing costs will be advantageous because of the simplicity of the devices.
Characteristic to the device according to the invention is the fact that the specimen cylinder has been attached to the frame of the gyratory compaction device mainly to be rotated with respect to its central axis. Constructions of the specimen cylinder which has been attached to be rotated with respect to its central axis as well as the upper and lower platens in the upper and lower part can be designed to be simple, rigid and very exact.
In an advantageous application of the device according to the invention a specimen cylinder has been mounted on bearings into a supporting construction, which has been attached to the frame in the way that the lower part is turnable. Because of the turnable attachment of the lower part, inclining of the specimen cylinder can be successfully carried out because of the simple exact and reliable construction.
In the second advantageous application of the device according to the invention there is a regulating device between the upper part of the supporting construction and the frame to incline the supporting construction and the specimen cylinder to a desired position. By means of the regulating device the specimen cylinder can be inclined to the desired position exactly and reliably.
In the third advantageous application of the device according to the invention a rotating device has been connected to the specimen cylinder in order to rotate the specimen cylinder and the specimen during the compaction. By means of the rotating device connected to the specimen cylinder, the specimen cylinder and the specimen can be rotated according to the demands of the test simply and advantageously.
In the fourth advantageous application of the device according to the invention a rotating device has been connected to the upper platen to rotate the upper platen and the specimen during the compaction. By rotating the upper platen, sliding between the specimen and the upper platen is prevented, and advantageous rotating motion with respect to the specimen is guaranteed, thus making the gyratory compaction device reliable and suitable for many various specimen materials.
In the fifth advantageous application of the device according to the invention a rotating device has been connected to the lower platen to rotate the lower platen and the specimen during the compaction. By rotating the lower platen the undesirable sliding of the lower platen and the specimen is prevented, thus making the gyratory compaction device function exactly and reliably.
In the sixth advantageous application of the device according to the invention the upper part of the specimen cylinder has been supported to the frame by at least two rolls mounted in bearings to the frame. Because of the support organised with the rolls, the mounting in bearings is simple, without clearances and rigid.
In the seventh advantageous application of the device according to the invention the rolls have been mounted in bearings to be moved with a regulating device to incline the specimen cylinder to a wanted position. Because of the rolls, mounted in bearings with regulating device, the specimen cylinder can be inclined in a functional way advantageously and exactly to the desired position.
In the eighth advantageous application of the device according to the invention the lower part of the specimen cylinder has been supported from the inner surface to the lower platen to mount in bearings the lower part of the specimen cylinder to the frame. Because of the support of the lower platen of the specimen cylinder, the mounting in bearings of the specimen cylinder is simple and economical to make and the lower platen can be used to rotate the specimen cylinder, thus, avoiding the need of a separate rotating device for the specimen cylinder.